In horror master Koontz’s latest nightmarish thriller, a man is stalked by the woman who donated the heart that saved his perfect life. Soon, ominous signs begin to appear: a box of candy hearts, a heart pendant and finally, a message that cites her claim. Malcolm Hillgartner’s straightforward reading lacks the raw emotion needed to excite the imagination of most listeners, excepting Koontz’s most diehard fans. Hillgartner’s stern voice does not come close to sounding like a 30-something Internet entrepreneur. With little connection between the words and the voice of the narrator, the result is lackluster and uninspired. A Bantam hardcover (Reviews, Oct. 27). (Nov.)